22.2.13

The following extracts are taken by permission from the unpublished work "On Poisons," by Dr. Alfred S. Taylor, F.R.S., accompanied by remarks by that gentleman: -

"There is one form of chronic poisoning by arsenic on which it will be proper to make a few remarks, as the real cause may remain wholly unsuspected. Arsenic is largely employed in this country, under the form of emerald green (aceto-arsenite of copper), and of orpiment in the manufacture of decorative papers with which the walls of sitting and bedrooms are covered. Some persons have suffered from symptons of chronic poisoning by arsenic, in which no other cause was apparent than the continued respiration of the air of their rooms, charged probably at times with a fine arsenical dust. On examining the papers, they will be found in some instances loaded with arsenic, laid on in a rough and coarse manner, so as to be easily removable by friction. Arsenic is thus used in imparting a green tint to some of the most costly as well as the cheapest decorative papers. It is a practice fraught with danger in more respects than one, and under a proper system of medical police, it would not be permitted. In the kingdom of Prussia, the use of these papers is strictly prohibited. If there has not hitherto been much complaint on the subject, it may be attributed to the fact that the cause has not been suspected. Many obscure cases of illness, referred at the time to constitutional and other causes, may probably have been due to the effects of arsenical dust thus inhaled day and night by those who inhabited the rooms. Dr. Hunds, who suffered from the effects himself, has described two cases in which the prominent symptoms were prostration of strength, headache,thirst, loss of appetite - an inflammatory state of the conjunctivæ with heat and dryness of the fauces. (Medical Times and Gazette, May 23, 1857, p. 521.) A portion of the paper of the room in which these persons lived was sent to me, and on examination I found in the green pigment spread over it, a large quantity of arsenic. These facts should at least be borne in mind in cases in which it is suspected that poison is being secretly administered to another.

"Dr. Traill met with a case in which a child aged three years suffered severely from symptons of arsenical poisoning, owing to its having sucked some slips of paper coloured with this green pigment; some of the paper, still retaining colour, was passed in the motions. The child recovered (Edinburgh Monthly Journal, July, 1851, page 1.)

"Among other uses of this noxious compound, we find it employed for imparting a bright green colour to the shelves of bakers' and green-grocers' shops. An incident which occurred to myself will show that food may thus acquire an arsenical impregnation. Several loyves of bread were supplied to me, having upon the undercrust a quantity of green-coloured pigment, which on analysis turned out to be arsenite of copper, contaiing about fifty per cent. of arsenic! On inquiry, I found that the baker had recently painted the shelves of his shop with this pigment, and the hot loaves placed upon them had taken off a portion of the arsenical paint. It is easy to conceive that an accident of this kind, if undetected, might lead to serious results, and perhaps to very erroneous suspicions. (Medical Times and Gazette, April, 1854, p. 326.)

"Another alleged form of poisoning by this substance which has attracted some attention, is in the state of vapour or fine dust applied to the membrane of the lungs, or in the state of powder as applied to the skin. In the former edition of this work the following case was related. A young man, after having been engaged for nine days in printing with an arsenical green pigment, was seized with irritation and warey discharge from the nose, swelling of the lips and nostrils, and headache. The next day he experienced severe colic, and great muscular weakness; but these symptoms disappeared in about eight days. It is probable that, in this case, the arsenite of copper had been taken into the body in the state of fine powder. (See Arsenical vapours, ante, p. 426.) I have since been informed, that the persons who manufacture and hang the coloured paper on walls, suffer from boils, inflammation of the eyes, and other symptoms of irritation. In one case now under treatment, pustular tumours have shown themselves on the writsts and ankles, and there is excessive sensitiveness and irritability of the skin. If removed the patients soon recover. In a former page I have alluded to the mytsterious deaths of a whole family (see cases of the Arzone family, ante, p. 120). The father was a pigment-manufacturer, and there is a great reason to believe that he and his family fell victims to the respiration of arsenical dust or vapours. According to M. Bouchardat (Annuaire de Thérapeutique, 1846, p. 209), the workmen who handle the emerald green in making the papers, are subject to serious disorders of health. They sometimes suffer from eruptions of the skin - one of the local effects of poisoning by arsenic (see Assoc. Med. Journal, 1856, Spet. 6, p. 271, 757; Sept. 20, p. 810, and ante, p. 371), with oedema (watery swelling) of the face, and boils frequently forming in the actorum. There is irritation with discharge of fluid from the mucous membrane of the nose, and abundant salivation. In the more advanced stage, there are colicky pains, headache, and prostation of strength. (See Ann. d'Hyg. 1847, ii. p. 56; and Journal de Chimie, Juillet, 1858, pp. 394, 397.)

"More than ten years since, Dr. Martin announced that the use of this arsenical green in oil-paint had an injurious effect upon those who inhabited apartments recently painted with this substance. Four pounds of Scheele's green had been used in painting the walls of a low damp room. In a few days a putrescent and highly disagreeable odour was perceptible. When the windows were closed, those who remained in the room experineced headache, pain in the chest, and other disagreeable symptons. The colour was scraped from the walls, and the room was then inhabited without any of these unpleasant symptons being observed. Dr. Martin attributed the effects to the production of arsenuretted hydrogen. The poisonous salt may, however, have been itself carried off in vapour, like white lead, under similar circumstances, by the oil of turpentine. In a note attached to this case, it is stated that since the mixed acetate and arsenite have been substituted for carbonate of copper in painting the walls of rooms, many persons who have slept in rooms painted green, have complained in the morning of headache, nausea, dryness of the mouth and throat, and cough. The symproms went off during the day. In one instance the foul odour was referred to mice, and the wainscot was about to be removed, when a suspicion arising that it was owing to the green colour used as a pigment, this was removed, and the smell disappeared. (Gaz. Med. 13. Fev., 1847, 180.)

"I have elsewhere referred to the probable effects of wall-papers loosely covered with the aceto-arsenite of copper (ante p. 364). This pigment contains fifty-nine per cent- of arsenic, and from some of these papers the noxious material may easily be scraped or removed by friction. A square foot of the paper may yield from twenty-eight to seventy grains of the arsenical pigment, and in rooms exposing five or six-hundred square feet, a large quantity of arsenic is thus distributed over an extensive surface. Dr. Hinds, of Birmingham, noticed, that in occupying a room which was covered with a wallpaper of this kind, he suffered from severe depression, nausea, pain in the abdomen, and great prostration of strength. These symptons appeared every evening that he sat in the room: this led him to suspect that they were connected with this room, and on examining the paper he found in it a quantity of arsenic. (Lancet, 1857, vol. i., p. 193). Two other cases occurred in his practice, where similar symptoms were produced in a man and his wife, under similar circumstances. To these I have elsewhere referred (ante, p. 365). Dr. Halley, of Harley-street, suffered from constant headache, dryness of the throat and tongue, with internal irritation. In about three weeks, he became completely prostrated, and was threatened with paralysis of his left side. He called on me and described his symptoms, bringing, at the same time, a portion of the wall-paper of the room in which he was in the habit of sitting; and this I found to be loaded with arsenic. He removed the paper, and since then has recovered his health. Several cases have since come before me, in which, whether rel or imaginary, symptoms of a similar kind have been referred by persons to the habitation of rooms papered with the arsenical green. At the same time, there have been many cases in which the occupation of rooms thus papered has been attended with no injurious effects. This fact, as well as a few imperfect experiments, have led some persons to affirm that the arsenical papers have not produced the effects ascribed to them. (see Pharmaceutical Journal, April, 1858, p.520, and May, 1858, p. 554). The connexion of cause and effect, however, appears to me to be too plainly made out in the cases of Dr. Hinds and Dr. Halley, to be set aside as a mere coincidence. The symptoms in both cases were similar, and such as arsenic is well known to produce; there was no other source of arsenic, and no other cause to explain them; and they entirely ceased on the removal of the arsenical paper. It may not be easy to detect arsenic in the air of a room thus prepared, but then it is equally difficult to detect lead in the air of freshly painted rooms, in which persons have been paralysed by passing a night. In the year 1837, and subsequently, arsenic was largely used in the manufacture of a spurious kind of wax-candle. The workmen suffered from boils and other disorders, and some who occupied rooms in which such candles were burnt, complained of symptoms like those of arsenical poisoning. As in reference to the arsenical papers, it was alleged, - because arsenic could not be detected in the air of a room, and all persons did not suffer from the use of the candles, that the illness was owing to some other cause. Although there are difficulties in explaining how it happens that more accidents do not occur, it appears to me there is already sufficient evidence to justify an enforcement of the Prussian regulation prohibiting the use of arsenic for such a manufacture, or in allowing the paper to be sold only on the condition that the words "arsenic, poison," are stamped upon it. (See Pharm. Journal, May, 1858, p. 553.)

"Dr. Böcker of Bonn, one of the most recent writers on Toxicology, refers to the effects of chronic poisoning produced on persons inhabiting rooms of which the walls are covered with arsenical paper hangings, and states, that on several occasions he has been called upon to treat such cases. A removal of the cause has generally proved sufficient. Dr. Böcker considers that a damp state of the wall renders them injurious. (Die Vergiftungen, 1857, p. 132.)"

Note. - I append an abstract of a notice issued by the Prussian government in reference to arsenical paper-hangings on the 3rd September, 1857. (Cuspers Vierteljahrschrift für Gerichtliche Medicin, Januar 1858, p. 184, Art, xxiii.)

"The Board of Police cannot too strongly impress on the public, the danger to health arising from the use of arsenical colours, especially in the habitation of rooms the walls of which are painted with such colours, or are covered with arsenical paper-hangings. The breathing of the vapours (air) in such rooms, has produced all the effects of slow poisoning by arsenic, namely, disordered digestion, difficulty of breathing, cough, colicky pains, weakness of the muscles, trembling and loss of power in the limbs, falling off of the hair, abscesses in the skin, emaciation, a wasting fever, and death. In removing arsenical papers from walls, they should be first well washed with salt-water, as the respiration of the arsenical dust may cause serious symptoms or death. The Board of Police earnestly entreat all medical men in thei respective districts to advise the removal of arsenical colours from the dwellings in which they may be used.

REMARKS. - It is not my intention to take part in the controversy which has arisen on this subject. It appears to me that it is leading the mids of the public from the true subject at issue. Mr. Phillips may be right in his conclusion that he could detect no arsenious acid in the air of a room covered with these poisonous paper-hangings; and "Crystallographer" may be right in assuming that the octahedral crystals seen by Dr. Halley may not have been arsenic but "microscopic diamonds" derived by some mysterious process from the carbon of the paper, or of the atmosphere. The wustion is not one of chemistry or crystallograpgy, but really one of pathology. Certain symptons, unquestionably those of arsenical poisoning, have arisen in certain persons who inhabited rooms of which the walls were covered with these papers. They have existed with the papers; they have disappeared on their removal. These facts are perfectly in accordance with those collected by the Prussian Government, and which have induced that overnment authoritatively to prohibit the use these paper-hangings.

Mr. Phillips brings forward his own case and that of his family, as a proof that the use of such papers is not noxious or injurious to the health. It would be easy to produce cases from the arsenic works of Cornwall, to show, by the exemption of some workmen, that the vapours of arsenic were not poisonous; and, from white-lead works, cases which show that many workmen do not suffer from lead poisoning; but it is well known that we are not all constructed alike in reference to the effects of poisons, and it is just possible that there may be a susceptibility to the action of arsenic in a few, while the majority may escape.

* Leading article in daily News, Sept. 1st, 1858.** Journal of Society of Arts, August 37th, 1858, p. [---]I must, however, express my surprise at Mr. Phillips's conclusion, which appears to me substantially to admit the great danger to which the use of these papers in our dwellings must expose us; whilst at the same time, his paper is leading the public to believe, because he found no "octahedral crystals," that there is no danger at all*. He says: -"In conclusion, I beg toexpress my opinion that no danger need be apprehended from a paper such as the one annexed, in which but a small proportion of the surface is unglazed, provided ordinary care be used when removing the dust from the walls, but that even if such care were not exercised, it is doubtful (!) whether any pernicious effect would be felt by those inhabiting the room."**

The questioon immediately suggest itself - What will happen in the dwwellings of those who cover their walls with cheaparsenic papers entirely unglazed? On eo fthese I have now before me, and the arsenical pigment is rubbed off the surface with the slighters friction. Again, it would appear from his statement that even the glased arsenical papers must be dusted with care. The breathing of the green dust of arsenite of copper may be just as fatal to life as the breathing of microscopic crystals of white arsenic; and, supposing that by careless dusting, &c., the poisonous material is diffused in a room, and is breathed by persons inhabiting it, it is by no [--- means?] doubtful but certain what the effects would be.

I am one of those who think that the fine and impalpable dust which is diffused through a room by currents of air, mechanical agitation, &c., is derived from the material on the walls as well as from the floor and ceiling. The walls generally present twice the extent of surface. If the powder on the walls is of an arsenical nature, it is not easy to perceive how, apart from the mechanical dusting of domestics (indispensable in most houses), we can prevent the occasional diffusion of a poisonous dust in an impalpable state. We are only made conscious of the existence of this diffused dust by the striking of a sunbeam across an inhabited room. They who prefer the "cheerful" green of an unglazed arsenical paper must, therefore, according to Mr. Phillips, be prepared to incur some risk - care must be taken that the walls are not too frequently or roughly dusted!

I have found, with respect to some of these papers, that they contain arsenic in a form soluble in water, and that in mixed patterns, parts of the papers surrounding the arsenical green colour are impregnated with arsenic. By scraping the arsenical pigment from the surface, or by soaking slips of the paper in water, the means of poisoning are always at hand. During the last summer I caused some of the arsenical paper to be moistened with water containing a small quantity of sugar. Flies which settled upon it were rapidly killed. As an objection to legislation for restricking the sale of arsenic, it was stated by a well-known pharmaceutist that arsenic might be easily procured for criminal purposes by scraping the walls of almost every dwelling house! This is an additional point for consideration in reference to the domestic use of this dangerous pigment. We require strong restrictions on the procuring of arsenic from a druggist's shop, and at the same time place the poison within reach of any evil-disposed person under such cirqumstances as to ensure secrecy of possession and use. A square foot of this paper contains enough arsenic to poison five or six persons.

In your Journal, Vol. v., p.652, and Vol. vi, p. 606, you have made a reference to my evidence on this subject before a Committee of the House of Lords. I may mention to you that the inquiry arose under these circumstances. Their Lordships desired to know what became of the large quantity of arsenic manufactured in and imported into this country. I informed them that a very large proportion was spread in the form of pigments over the walls of our dwelling houses. I have since learnt that one London manufacturer alone was in the habit of using about two tons of arsenic per week in the production of this green pigment for paper-hangings! Its cheapness and durability as a colour recommend it strongly to public notice. Since the evidence which I have before the Committee of the House of Lords, fifteen months ago, I have had still stronger reasons for holding the opinion then given respecting the danger attending the use of these papers. Mr. Phillips suggests glazing and [---] dusting. I would suggest that some other green colour should be selected, even at a little more cost. If the manufacture of arsenical papers is to be continued, the Prussian poison-symbol of a skull and cross-bones, with the motto Memento mori, should be printed as a pattern upon it - or, at least, it should be intimated to all who purchase the paper-hangings that they contain arsenic.

The following paper, by Dr. William Hinds, bearing immediately upon the same subject, is extracted from the Pharmaneutical Journal for the 1st. inst. : -

Certain carefully-prepared papers, which recently appeared on the above subject in the pages of the Pharmaceutical Journal, not having beem, as far as I am aware, [---] replied to, I beg to ofer to the readers of the above interesting journal a few observations on this subject. [---] confusion of ideas seems to prevail extensively as to the facts brought before the public, while even the deleterious influence is itself denied in some quarters. It is by no means uncommon to see theoretical denials and disputes by some persons, in reference to facts and truths, which are nevertheless characterised by such stern features as tobe realised as facts and truths by others. The views advanced by myself and others as to the injurious effects of arsenical papers in rooms, I believe to be unquestionable. Arsenite of copper, as a poisonous pigment, I find frequently recognised by writers on medical jurispudence; but so far as I have been able to learn, to Dr. Alfred Taylor belongs the merit of more especially commenting upon the dangers to be apprehended from its employment. In his invaluable work, Dr. Taylor gives a case, in which "a young man, after having been engaged for nine days in printing with this arsenical green, was seized with caryza, swelling of the lips and nostrils, and headache. The next day he experienced severe colid and great muscular weakness." Dr. Taylor adds the valuable remark, that "in this case the arsenite of copper had been taken into the body in the state of fine powder."

This shows that Dr. Taylor's attention had been specially drawn to the subject. At hte same time I may remark, that to the best of my knowledge, no case of actual poisoning had ever been made public, as having occurred from simply inhabiting a room gung with the arsenical paper, until my own case was published in the Medical Times and Gazette in February, 1857. The accident occurred to me as far back as 1849; but the case being, as I then thought, so unique and unparalled, I hesitated to publish it until I had had means of collecting other cases, or until a favourable opportunity.

The way in which I was led, step by step, to certain conclusions as to the injurious effects, and also a description of these effects, are given exactly as they occurred in the paper mentioned, and to which I beg to refer those who may feel an interest n this subject.

In the next cases which came under my notice, the moral force of the evidence was so strong, as to satisfy the most sceptical. The injury occurred to a Mr. simpson, of this city, and to his wife. Mr. S. had enjoyed the best health until he had a green flock paper put on the walls of two sitting-rooms. In a very few days he experienced all the symptoms of slow arsenical poisoning, but without either believing in, or even suspecting the cause. He became seriously ill, as also did his wife; and a fine parrot, which was hung in one of the rooms, all at once drooped and refused food. At this stage a gentleman, who had known of my own case, suggested a solution of the mystery as to the cause of the illness, but Mr. S. repudiated the supposition. He then left town for his health, returning in a fortnight quite strong and vigorous, and confident he should continue so. In several days he became again seriouysly ill, and after long residence, he became deeply convinced, by the very force of circumstances and suffering, that the cause lay in the wall paper. He underwent the expense of an entire removal of the paper, and soon after all were well. The gentleman here mentioned, would, I am sure, be glad to give his experience to any person who might be sceptical as to the facts.

Mr. S.'s case is fully detailed, without names, in the scientific journal before mentioned, for May, 1857.

In the case published by Dr. Halley in the Times newspaper, the facts and results are as striking and forcible as in the other published cases.

I have to say one word as to the mode of escape from these arsenical papers of the poisonous colouring matter, and I must observe that a vast deal of entirely irrelevant speculation and equally futile experiments have been expended, with a view to disprove facts, about which it is astonishing that any reasoning person can have a just doubt. A sample of this irrelevancy I will presently mention.

I find papers in this journal for May and June, evidently from able contributors, denying our conclusions, which the space could request would not enable me extensively to notice. For this, however, there is the less necessity, inasmuch as the writers give but negative results for the most part. I believe I am justified in saying that our positive facts and forcible moral evidence are not shaken by mere negative results, and miniature and usually irrelevant experiments. neither is the question a mere chemical one, to be easily decided in miniature. The existence of the poisonous ingredient upon the paper is admitted, though one gentleman seeks to spoil this admission, by asserting (truly enough) that the flock portion is a mere dyed stuff, and contains nothing injurious. The injurious effects, moreover, of arsenite of copper, when inhaled, are equally admitted. Now, that mere water-colour pigment, without an overcoat of varnish, will give off, under certain hygrometric conditions, particles of its dust to the atmosphere, is perhaps so self-evident as not to require any laboured proof. The fact is indeed unquestionable. Take a feather or a soft white napkin, and run either never so lightly over a green paper of the ordinary kind, after it shall have been placed upon a wall by means of paste, and myriads of particles of the colour from the surface will adhere. Much, of course, is sent floating in the atmosphere of any room by the last possible disturbance of its contained air, as by draughts or the opening of doors. These particles will be then breathed into the lungs, and produce all the symptoms which have been described. A great deal has been said about volatilisation of arsenic and arsenical vapour, but it is not all to the purpose. Dr. Taylor's idea, as given in this journal for May last, and the same as it presented itself to me in the first case published, is, I believe, the only rational one - namely, that the finer and lighter particles of the colour escape as such. Now, what is the dose of this fine powder of Scheele's green necessary to produce bad symptons? That is a question to which I cannot give an answer. Probably it is extremely small in quantity. Dr. Taylor, whose labours place him at the head of his department, in this country at least, has not attempted, so far as I know, to give a reply to this question; and the means by which the deleterious particles become active in the system, present several difficulties not easily to be solved.

There is one experiment I would beg to urge strongly upon the gentlemen who are spectical as to our facts. It is that they should place themselves in the same conditions as those under which our facts were gathered. I shall be happy to furnish any gentleman who may wish to make the experiment, with samples of arsenical paper from which to select. Let a room be papered with one of these, and let the experimenter undergo the same experience as we who have suffered, and I shall have little doubt that he will come out of the trial fully convinced. It would be still better to make a series of trials, in order to avoid any incidental negation.

I may here mention the fact of the universal testimony [] workmen who have been in the habit of hanging green [hangings?] [---] the often severe sympoms which the experience [---] at work. One most powerful man, a paper [---] me he has repeatedly got so ill with caryza, [---] , and prostation, while hanging green [---] has been compelled to leave the room, and [---] to finish his work. This man could tell [---] that green paper was very injurious, though [---] to be told that the colour was arsenical. [---] to be borne in mind, that in all these [---] were of the kind indicative of slow [---] -enteritic irritation, with [---], nausea, prostation, loss of muscle [---] and dryness of throat; and [---] the cause was at first entirely [---]. In my own case I [---] notice to the colour of [---] myself with an examination [---] suffering illness that my attention was gradually attracted to every altered condition of the room for years with no inconvenience. The sympotoms came on in three or four days after the papering. They ceased on my ceasing to occupy the room. They recurred every time I had sfor some hours again used it, and they never appeared after the room was stripped of the injurious paper. Tje very same conditions, or very similar, were experienced by Dr. Halley, whose communication on the subject appeared in the Times of the 11th of January of the present year; and the same also in Mr. Simpson's case, to which I have before alluded.

I will now gove a speciment of the "experimetns" by which the facts we bring forward have been met. Several experiments have been detailed in this journal by Mr. F. A. Abel. I desire to be entirely just to Mr. Abel's efforts, but I cannot think his scientific knowledge was present to him at the time of those experiments. I will explain my meaning. On coming to the sevent experiment, Mr. A. Makes the following most remarkable statement. He says: "It should be mentioned that in all these experiments, the tube was plugged with cotton wool." Now we refer to the other conditions of these experiments, and we find that the temperature is raised to only 90° on the one hand, and on the other, the tube was plugged with cotton wool, to allow no particles to escape mechanically! Mr. Abel will forgive me for reminding him of a fact he already knows - namely, that arsenic can only be voltilised by heat at a temperature of 380°; and yet he sticks to 90°, and plugs the escape-tube with cotton-wool, to prevent the mere mechanical passing of arsenic. I am sure Mr. A. will see the entire inconsistency and inapplicability of his whole experiments, on a reconsideration of the subject.

In Mr. Dugald Campbell's experiments, given with candour and clearness, the conditions were essentially different from those in which arsenic is given off in a room; for while the 140°, the highest point to which Mr. C. raised the temperature, were less by no smaller a quantity than 240° than the temperature required for the volatilisation of arsenic; a square foor only of paper, and confined in a bottle, is a very different thing from a square foot, indeed I might add 500 square feet, or 1000, pasted upon a wall, and subject to certain important hygrometric transitions, which favour the loosing of the colour, and its escape into the atmosphere of the room.

Some observations have also been made in the journal by Mr. B. H. Paul, and are given with great condour. Those remarks contain no experiments on the subject in question, and, as they are directed more especially against the gratuitously-conceived theory of vaporisation of pure arsenic by heat, inapplicable in the present case, require little remark. In conclsion, I may express my regret to perceive how completely an ascertained fact, as communicated by Dr. Taylor, in reference to the actual observance of particles of Scheele's green upon a slip of glass, can be ignored by a mere surmise.

21.2.13

The following letter, addressed to the editor of the Daily News, and published in that paper on the 13th inst., has been forwarded to the editor of the Society's Journal by Dr. Halley: -

Sir, - In your number for the 1st of the present month, which I have only just had an opportunity of perusing, there is a leading article on the above subject, in which allusion is made to a statement of mine, the validity of which you assert to have been controverted by the experiments and opinion of Mr. Phillips, the chemist to the Board of Inland Revenue. May I crave the indulgence of your space whilst I correct a misconception into which that gentleman has fallen, and at the same time cindicate the correctness of my own assertation.

The only communication that I have yet made upon this subject was that contained in a letter to the [Time] of the 11th January last, a letter hastily written on the spur of teh moment, in reply to one by Mr. Fletcher, purposely condensed as much as possible, but containing a plain statement of facts as they occurred, with the simple view of warming others, and, if possible, to prevent the suffering I had myself undergone.

This letter was copied nearly entire into the number of the Pharmaceutical Journal for February last.

In the number of the Journal of the Society of Arts for the 27th August last, at page 606, Mr. Phillips, taking the report in the Pharmaceutical Journal, entirely misconceives, or at any rate misquotes, my statement, for he says: "It is stated that Dr. Halley, of Harley-street, had detected arsenious acid in the atmosphere of his study, the walls of which were covered with green paper, and that the test he employed was 'sheets of paper soaked in a solution of ammonio-nitrate of silver,' and that upon this paper were deposited numerous well-defined crystals of arsenious acid." This is not what I stated, and I am surprised that any chemist should place such a miscontruction upon the words I used. The merest tyro in chemistry should be perfectly aware that arsenious acid could not be so deposited. What I did state was this: "The air of teh room was next carefully tested (by means of sheets of paper soaked in a solution of the ammonio-nitrate of silver, a very delicate test of arsenic), and distinct crystals of arsenious acid, visible under a low power with the microscope, and sufficiently well defined and numerous to preclude the possibility of mistake, were obtained on two repeated and separate occasions." In writing to a non-professional journal I did not enter into every step of an analysis of a purely chemical nature, but gave the results of the experiment, merely indicating between brackets the key to the means used, that any chemist curious in the matter might repeat the experiment, filling up, of course, the blanks left in the description of the process. The obtaining of arsenious acid crystals was a positive and conclusive result - the fact - terminating the whole experiment, the commencement of which was the suspension in my room of sheets of paper soaked in the solution of ammonio-nitrate of silver, which in their turn were submitted to reduction, and so on to the result, the process being that known as Reinach's test.

But Mr. Phillips questions the fact of the crystals obtained being really those of arsenious acid; on the contrary, asserting that they were "more than probably" those of nitrate of silver. Without laying claim to any great knowledge of crystallography, which you assert is my presumption, it requires no great amount of acumen to distinguish between the decided octahedra of arsenious acid and the tabular plates of nitrate of silver, not to inention the impossibility of the resulting crystals in the experiment described being those of the latter substance.

Again, Mr. Phillips has misquoted my opinion as to the mode in which the arsenic is given off from the paper. I have not asserted, nor do I believe, that the arsenic contaminates the air in the form of arsenious acid. This is a very difficult point to determine, requiring more time and attention than I have had to spare from my professional avocations; but that, under certain circumstances, arsenic does contaminate the air of rooms covered with those papers to a most deleterious extent I firmly re-assert; and shall be most happy - I won't say convince, but - to show Mr- Phillips or any other chemist interested in the point the results of the experiments alluded to, upon which this opinion is founded.

And now, sir, in regard to the counter-experiments of Mr. Phillips and others, I am not prepared to explain in what manner, in every instance, they have failed to obtain similar results. It is not easy from mere description to judhe of an experiment involving minutiæ of manipulation; but knowing the quantites experimented with, and the very minute results I obtained - knowing also that those results would have been overlooked but for the use of the microscope, which Mr. Phillips, in common with many of his school, seems to disparage - I confess that his experimetns, although, I have no doubt ably and apparently impratially conducted, have in no way shaken my confidence in those alluded to in my letter, conducted as they were with the kind and able assistance of Mr. williams, of New Cavendish-street, a gentleman shose extensive experience as a wholesale manipulator is well known. The tests used were all prepared by him, and he kindly undertook many of teh minutiæ of the analysis. It is however but fair to state that in several similar experiments I failed to obtain similar results - showing that it is not all arsenically coloured papers that give off the poison, and this may explain why some persons have not suffered from inhabiting rooms so papered; but, on the oter hand, I re-asserts, for I known from personal experience and from numerous instances to my own knowledge well authenticated, that many persons have suffered from this cause.

The following is the passage in the article from the Daily News of the 1st inst., referred to above: -

The old proverb, that a "little knowledge is a dangerous thing," if not to its possessor at least to others, has been well exemplified by some recent chemical investigations. The progress of chemistry of late years has been so rapid that its most enthusiastic students have had hard work to keep pace with its advance. It has accomplished such marvels, and shown such usefulness in improving the manufacture of so many of the conveniences and even necessaries of every-day life, that we have all learnt to treat the opinion of the chemist at least with respect, if not with something approaching the most profound deference.

If the chemist is to retain that position, he can only secure it by the name not being usurped by those who really have no title to it. Those who do assume a knowledge of the science must also be careful not to step beyond the legitimate conclusions of their analysis, or substitute imagination or presumptuous assertion for demonstration.

In the evidence given by Dr. Alfred Swaine Taylor before the Committee of the House of Lords, on the "Sale of Poisons Bill," he alarmed their Lordships by describing the injurious effects of paper-hangings coloured with the arsenite of copper. Knowing the reputation of Dr. Taylor as a chemist, we have felt very uncomfortable since when sitting in any room covered with pretty green paper - especially if a gas-light has been burning. Our terror seems to have been partly shared by the Commissioners of the Inland Revenne Department. Their new offices had been hung with the poisonous paper, chosen no doubt for its refreshing colour. Instead of at once tering down the obnoxious paper, they proceeded according to the customary rule of routine; their attention having been calle to the circumstance they directed Mr. Phillips, the Chemist to the Board, to investigate the subject, and report.

The devotedness of the Commissioners is most admirable. We can fancy the conscious sense of martyrdom wit which they [-at] environed with supposed arsenical atmosphere, while their chemist was preparing his Report. We knew not that we possessed a Board who would sacrifice their own health, rather that put the tax-payers to the expense of re-papering their offices. We congratulate them on the result of their officer's Report, and that they have now the pleasing assurance that their devotion has not filled their bones and livers with arsenic, to be produced by Professor Taylor, on some post-mortem, for the edification of a coroner and his jury.

Mr. Phillips set about the investigation in a very proper an sensible manner. Two small closets were papered with the suspected covering. No ventilation was allowed, save that admitted round the chinks of the doors. The air was thus necessarily longer in contact with the paper that it would have been in an ordinary room. Both closets were carefully closed for 72 hours, and in one a gaslight was kept burning 45 hours. The most delicate re-agents for testing the atmosphere of the closets were used without detecting the slightest trace of arsenic. It may be asked, then, how did these papers acquire so bad a name?

Las February a physician communicated to the Pharmaceutical Journal that he had detected arsenious acid in the atmosphere of his study, the walls of which were covered with green paper. The test he made use of for determining this fact was the hanging in his room "sheets of paper soaked in a solution of ammonia and nitrate of silver." After a time he found the paper covered with numerous well-defined crystals of arsenious acid, visible under a low power with the microscope. Mr. Phillips hung paper similarly prepared in his experimental closets. his paper was covered with crystals, but analysis proved these crystals to be composed of nitrate of silver, derived from the solution in which it had been dipped. Mr. Phillips therefore assumes, and we think with perfect justice, that if the learned Physician had trusted less to his presumed knowledge of crystallography, and tested his crystals, instead of jumpung at the conclusion that they were composed of arsenic, he would have found them nothing more than nitrate of silver.

It may be some consolation for those of our readers who inhabit rooms papered with pretty green patterns, to learn that Mr. Phillips and his family have occupied a sitting-room covered with a paper heavily laden with arsenite of copper, for three years, without experiencing the slightest ill effect, though his bed-room during the whole time was papered with arsenical hangings. This is not, however, the principal reason why we have noticed Mr. Phillips's admirable Report. It is, we conceive, of the greatest importance that the public should be put on their guard against the too easy reception of assumed chemical conclusions.

We have no doubt of the perfect good faith of the physician who called the attention of the public to his presumed discovery. He did so from a praiseworthy motive. But we hope the exposure of his defective analysis will caution others from intruding their imperfect determinations on the public, to the serious detriment, it may be, of their honest neighbours.

-------------------------

The following letter, in reply to Dr. Hallery, appears in the same journal for the 14th inst.: -

To the Editor of the Daily News.

Sir, - Dr. hallery has endeavoured to show, that in your leading article on the hasty conclusions formed by some chemists you have done him an injustice. He believes that you have been misled by the report of Mr. Phillips, the chemist to the Board of Inland Revenue.

Now, sir, I do not believe that you have been misled in the slightest particular, or done any injustice to Dr. Halley. What are his own statements in defence of his analysis? He says that he tested the air of the room covered with arsenical dyed paper by means of sheets of paper soaked in a solution of the ammonio-nitrate of silver, that these sheets of paper, after exposure, were reduced, submitted to a test know by the name of reinsch, and that by this means he obtained crystals sufficiently large to be seen under a low power of the microscope.

Because these crystals were decided octahedra, he maintained that they were crystals of arsenious acid. You, sir, complain, and so do I, that because Dr. Halley saw crystals of the form assumed by arsenious acid under certain circumstances, he jumped at the conclusion that the form of the crystal was a sufficient evidence to identify the substance. Now, sir, I have devoted a little attention to the subject of crystallography, and I therefore know that there are a vast number of substances besides arsenious acid which will crystallise as regular octahedra. Dr. Halley had paper soaked in a combination of ammonia, silver, and nitric acid. He submits this paper, after its exposure to an atmosphere contaminated by gas, to certain tests. The paper had therefore, in all probability, absorbed the element of sulphur, either in a simple state or combined with certain gases. Can Dr. Halley, therefore, take upon himself to assert, that the octahedral crystals could not have been formed from certain chemical combinations made during his experiments, which may not have contained a single particle of arsenic or arsenious acid? Is he sure that these octahedra were not crystals of sal ammoniac?

His sheets of test paper contained ammonia, the paper itself was probably not free from the chlorine it had absorbed in its manufacture. Is it not therefore as probable that the crystals he saw under his microscope were a combination of chlorine and ammonia, which will assume the form of a perfect octahedron, as that they were formed from a combination of arsenic and oxygen derived from the atmosphere? Which is more probable? That the crystals were formed from the combination of substances supposed to be derived from the atmosphere. But taking into consideration the known impurities of the atmosphere, these might have combined with some of the ingredients contained in or introduced into the paper, so as to form combination, known to crystallise in the form of the regular octahedron.

For any evidence Dr. Halley has given us to the contrary, he may have actually produced diamonds without being aware of his valuable discovery. Both his paper and the atmosphere contained carbon. The diamond, as pure carbon, assumes frequently the form of the perfect octahedron, in its crystals. If form be a certain test as to chemical composition, what evidence had Dr. Halley adduced that his so-called crystals of arsenious acid may not have been microscopic diamonds.

Dr. Halley admits that he was satisfied that because he saw crystals which he assumed to be perfect octahedron, these crystals were necessarily composed of arsenious acid, because he suspected the presence of arsenic in the atmosphere. It is of his rash conclusion that Mr. Phillips complains. He examines the atmosphere of a room far more likely to be impregnated with arsenic than that examined by Dr. Hallery, without discovering the slightest trace of that deleterious substance. Mr. Phillips is a chemist, Dr. Halley a microscopist. Dr. Hallery gets a friend to manipulate the chemical part of his tests for him. Trusting to the deceptive form of his crystals, he neglects to submit these crystals to any test but this form. That form belongs to a host of substances [---] arsenious acid; therefore Dr. Halley's ambiguous [---] cannot be taken ans any confutation of Mr. Phillips's analysis.

Dr. Halley wrote his account of his experiments vaguely as to lead Mr- Phillips to infer, as one reasonably might have done, that the microscopical crystals were deposited on the surface of the test papers. Mr. Phillips found his paper covered with crystals of nitrate of silver, he, therefore, hazarded the opinion that Dr. Halley's crystals, if tested, would probably have been found to be simply nitrate of silver. To this Dr. Halley replies, that it requires no great amount of acumen to distinguish between the dediced octahedra of arsenious acid, and the tabular plates of nitrate of silver. If Dr. Halley will consult Phillips's translation fo the Pharmacopeia, which I have no doubt he possesses, he will see there that the author of that work states that the octahedral faces of crystals of the nitrate of silver sometimes are [---] englarged as nearly to obliterate the rhombic faces. It would require a very delicate eye to dintinguish the octahedra of nitrate of silver, with their upper and lower angles replaced by a plane, from the regular octahedra of arsenious acid, with their upper and lower angles replaced, as they frequently are, by planes of the cube.

Without actual goniometrical measurement, it is extremely difficult to distinguish the regular octahedron from some of the octahedra of both the square prismatic and the rhombic systems.

I would recommend Dr. Halley to repeat his experiments, and when he has obtained his octahedra, to sumbit them to such chemical tests as may satisfactorily determine their substance. Till he does so, he has no answer to Mr. Phillips's tests, nor will his negative crystalline evidence satisfy aCRYSTALLOGRAPHER.

20.2.13

In the Journal, Vol. V., p. 652, reference was made to the evidence of Dr. Alfred Swaine Taylor, given before a Committee of the House of Lords on the "Sale of Poinsons Bill," in which he spoke of the injurious effects of paper-hangings coloured with arsenite of copper. Some of the rooms in the new offices of the Inland Revenue Department being hung with these papers, and the attention of the Commissioners having been called to the circumstance, they directed Mr. Phillips, the chemist to the Board, to investigate the subject.

The following is the report: -

"In the Pharmaneutical Journal of February last, page 429, it is stated that Dr. Halley, of Harley-street, had detected arsenious acid in the atmosphere of his study, the walls of which were covered with green paper, and the test he employed was 'sheets of paper soaked in a solution of ammonia-nitrate of silver,' and that upon this paper were deposited numerous well-fefined crystals of arsenious acid, visible under a low power with the microscope, and that the form of these crystals precluded the possibility of a mistake.

"Ammonia-nitrate of silver is a test of arsenious acid, but not in the manner which Dr. Hallery seems to suppose, as it does not cause the deposition of crystals of arsenious acid (which are colourless), but produces a bright yellow precipitate of arsenite of silver. If such be not the case, no precipitate is produced. These particulars are mentioned because Dr. Halley appears not to have resorted to any other test, but to have concluded merely from the apprearance of the crystals fromed on his test paper, and without analysing them, that they must be those of the poison in question.

"In the following experiments, made with a view to test Dr. Halley's conclusions, the interior surfaces of two closets were covered with green paper similar to the pattern annexed.

"Closet A had a capacity of 17 cubic feet, and was lined with about 48 square feet of the paper, or 2-8 square feet to each cubic foot of space.

"Closet B had a capacity of 36 cubic feet ,and was lined with 53 square feet of paper, or 2.0 square feet to each cubic foot of space.

"These closets had no means of ventilation [---] the chinks round the doors; the included air, therefore, would remain much longer in contact with the paper than would be the case in an ordinary room. The surface of the paper to the bulk of air enclosed was not less than fourteen times as great as it would be in a room 20 feet square and 12 feet high, thus showing that the conditions of the experiments were highly favourable to the impregnation of the air with arsenious acid, if such were possible. In each of these closets were placed two basins, one containing a solution of potash, the other ammonia-nitrate of silver, and a sheet of paper saturated with the latter reagent. Closet A was kept as much as possible from the influence of common gas. In closet B gas was allowed to burn during the day-time, the temperature of the included air being kept by the flame at from 74° to 82° F. The closets were carefully closed for 72 hours, the gas burning during that time 45 hours in closet B. The solutions of potash and ammonia nitrate of silver from each closet were then examined by Marsh's test, which is by far the most delicate known, and found to be quite free from arsenic.

"The sheets of paper saturated with ammonia-nitrate of silver were also free from arsenic, but had on their surface numerous colourless crystals which, when analysed, proved to be nitrate of silver, the evaporation of the water from the test-paper having concentrated the solution with which the paper was saturated to such an extent as to cause the nitrate of silver to crystallize out. On the test-paper was also found an amorphous substance having a dingy yellow colour; which speedily became black on exporure to light; the same substance was also observed on the surface of ammonia-nitrate of silver contained in the basins, being most abundant in that which had remained in closet B, in which gas had been burnt. When analysed it was found to be sulphide of silver, the sulphur, no doubt, having been derived from the atmosphere of the laboratory, which always contains traces of sulphuretted hydrogen. This dingy yellow substance, which, without analysis, might be supposed by some to be arsenite of silver, was formed in a third closet, in which no arsenical compounds were present, thus proving that the green paper had no share in its production.

"The green paper used in the experiments is copured with what is known as emerald or Schweinfurt green, which is a compound of arsenite of copper and acetate of copper. The paper contains 11.8 grains of arsenious acid to the square foot. " The following conclusions may fairly be drawn from the experiments above described:-

"1st. That even when a small bulk of air is allowed to remain for a considerable time in contact with a large surface of the arsenical paper, and that [---] at a temperature of 80° F., not the slightest trace of arsenious acid is diffused in the air. Still less might [---] air of an ordinary room, which occupies a large surface in proportion to the surface of the walls, and which is being constantly changed by ventilation, be expected to become contaminated by the poison.

"2nd. That the products of the combustion of gas do not facilitate the libreation of arnesious acid from the surface of the green paper.

"3rd. That arsenious acid is not volatilised from the surface of such paper except at temperatures too high for human endurance.

"It is probable that persons may have been affected by habiting rooms papered with arsenical hangings, not because the arsenious acid has been volatilised, but from the improper and frequent sweeping of the walls, by which minute particles of arsenite of copper might be [---] from those portions of the surface of the paper which were not glased, and becoming dispersed in the air, might be inhaled by persons occupying the room at the [---] . This only soirce of danger, which might be objected by a little management in the cleaning of a room, [---] in the selection of a paper having but a little of its surface unglazed, apperars not to have presented itself to the mind of Dr. Halley, who seems to have been possessed with the idea that injury to health was to be apprehended solely from the vapourisation of the arsenious acid. Dr. Taylor, on the other hand, ascribes the danger to the fact that the colour is 'put on very loosely,' and, therefore, by inderence, easily detached and disseminated through the air, not as vapour of arsenious acid, but as minute particles of arsenite of copper.

"The subject under consideration being one of much importance, I have felt it necessary to enlarge upon it, and as Dr. Halley's statement is calculated to create an apprehension of danger which I believe has no existence, I beg to make the following remarks: -

"Dr. Halley states that on two occasions distinct crystals of arsenious acid were deposited on the surface of his test-paper from the air of his room. It is more than probable that if he had analysed the crystals, and not assumed their composition from their appearance under the microscope, he would have found them to be nitrate of silver. The test-paper which he used had no more effect in causing the deposition of crystals of arsenious acid than any other surface in the room would have, and to suppose that crystals of the poison were thus deposited, would be to imply that the air was impregnated with arsenious acid to an extent which must be fatal to persons inhaling it for a short time. Notwithstanding his statement that the air of his room furnished crystals of arsenious acid, he subsequently says that, at ordinary temperatures, with common atmospheric air, even when an aspirator was used, the amount of arsenic given off was 'inappreciably small,' omitting to mention what test he employed to detect a quantity not appreciable. Tje purport of his remarks, however, appears to be that arsenious acid, to an appreciable extent, is only given off from arsenical paper in rooms in which gas is burnt, and what the products of the combustion of the gas combine with the arsenic in the paper. If such be the case, it is difficult to conceive how the arsenious acid can be deposited from the air of the room in a free and crystalline state.

"It may be proper to mention that I and my family occupied a sitting-room three years, the walls of which were covered with paper heavily laden with arsenite of copper, and that for the same period my bed-room was also papered with arsenical hangings, yet neither I nor any member of my family experienced the slightest ill effect from such paper.

"In conclusion, I beg to experss my opinion that no danger need be apprehended from a paper such as the one annexed, in which but a small proportion of the surface is unglazed, provided ordinary care be used when removing the dust from the walls, and that even if such care were not exercised, it is doubtful whether any pernicious effects would be felt by those inhabiting the room."

NOTE!Coloriasto is an archive website about colour related stuff. The main language of the site is Finnish. The recipies & such may contain poisonous and hazardous materials and are not intended to be executed/realized. This material is collected for those who are interested about the history of colours, pigments, paints and dyes.